drivers/dma/qcom/bam_dma.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2013-2014, The Linux Foundation. All rights reserved.
   4  */
   5 /*
   6  * QCOM BAM DMA engine driver
   7  *
   8  * QCOM BAM DMA blocks are distributed amongst a number of the on-chip
   9  * peripherals on the MSM 8x74.  The configuration of the channels are dependent
  10  * on the way they are hard wired to that specific peripheral.  The peripheral
  11  * device tree entries specify the configuration of each channel.
  12  *
  13  * The DMA controller requires the use of external memory for storage of the
  14  * hardware descriptors for each channel.  The descriptor FIFO is accessed as a
  15  * circular buffer and operations are managed according to the offset within the
  16  * FIFO.  After pipe/channel reset, all of the pipe registers and internal state
  17  * are back to defaults.
  18  *
  19  * During DMA operations, we write descriptors to the FIFO, being careful to
  20  * handle wrapping and then write the last FIFO offset to that channel's
  21  * P_EVNT_REG register to kick off the transaction.  The P_SW_OFSTS register
  22  * indicates the current FIFO offset that is being processed, so there is some
  23  * indication of where the hardware is currently working.
  24  */
  25
  26 #include <linux/kernel.h>
  27 #include <linux/io.h>
  28 #include <linux/init.h>
  29 #include <linux/slab.h>
  30 #include <linux/module.h>
  31 #include <linux/interrupt.h>
  32 #include <linux/dma-mapping.h>
  33 #include <linux/scatterlist.h>
  34 #include <linux/device.h>
  35 #include <linux/platform_device.h>
  36 #include <linux/of.h>
  37 #include <linux/of_address.h>
  38 #include <linux/of_irq.h>
  39 #include <linux/of_dma.h>
  40 #include <linux/circ_buf.h>
  41 #include <linux/clk.h>
  42 #include <linux/dmaengine.h>
  43 #include <linux/pm_runtime.h>
  44
  45 #include "../dmaengine.h"
  46 #include "../virt-dma.h"
  47
  48 struct bam_desc_hw {
  49         __le32 addr;            /* Buffer physical address */
  50         __le16 size;            /* Buffer size in bytes */
  51         __le16 flags;
  52 };
  53
  54 #define BAM_DMA_AUTOSUSPEND_DELAY 100
  55
  56 #define DESC_FLAG_INT BIT(15)
  57 #define DESC_FLAG_EOT BIT(14)
  58 #define DESC_FLAG_EOB BIT(13)
  59 #define DESC_FLAG_NWD BIT(12)
  60 #define DESC_FLAG_CMD BIT(11)
  61
  62 struct bam_async_desc {
  63         struct virt_dma_desc vd;
  64
  65         u32 num_desc;
  66         u32 xfer_len;
  67
  68         /* transaction flags, EOT|EOB|NWD */
  69         u16 flags;
  70
  71         struct bam_desc_hw *curr_desc;
  72
  73         /* list node for the desc in the bam_chan list of descriptors */
  74         struct list_head desc_node;
  75         enum dma_transfer_direction dir;
  76         size_t length;
  77         struct bam_desc_hw desc[];
  78 };
  79
  80 enum bam_reg {
  81         BAM_CTRL,
  82         BAM_REVISION,
  83         BAM_NUM_PIPES,
  84         BAM_DESC_CNT_TRSHLD,
  85         BAM_IRQ_SRCS,
  86         BAM_IRQ_SRCS_MSK,
  87         BAM_IRQ_SRCS_UNMASKED,
  88         BAM_IRQ_STTS,
  89         BAM_IRQ_CLR,
  90         BAM_IRQ_EN,
  91         BAM_CNFG_BITS,
  92         BAM_IRQ_SRCS_EE,
  93         BAM_IRQ_SRCS_MSK_EE,
  94         BAM_P_CTRL,
  95         BAM_P_RST,
  96         BAM_P_HALT,
  97         BAM_P_IRQ_STTS,
  98         BAM_P_IRQ_CLR,
  99         BAM_P_IRQ_EN,
 100         BAM_P_EVNT_DEST_ADDR,
 101         BAM_P_EVNT_REG,
 102         BAM_P_SW_OFSTS,
 103         BAM_P_DATA_FIFO_ADDR,
 104         BAM_P_DESC_FIFO_ADDR,
 105         BAM_P_EVNT_GEN_TRSHLD,
 106         BAM_P_FIFO_SIZES,
 107 };
 108
 109 struct reg_offset_data {
 110         u32 base_offset;
 111         unsigned int pipe_mult, evnt_mult, ee_mult;
 112 };
 113
 114 static const struct reg_offset_data bam_v1_3_reg_info[] = {
 115         [BAM_CTRL]              = { 0x0F80, 0x00, 0x00, 0x00 },
 116         [BAM_REVISION]          = { 0x0F84, 0x00, 0x00, 0x00 },
 117         [BAM_NUM_PIPES]         = { 0x0FBC, 0x00, 0x00, 0x00 },
 118         [BAM_DESC_CNT_TRSHLD]   = { 0x0F88, 0x00, 0x00, 0x00 },
 119         [BAM_IRQ_SRCS]          = { 0x0F8C, 0x00, 0x00, 0x00 },
 120         [BAM_IRQ_SRCS_MSK]      = { 0x0F90, 0x00, 0x00, 0x00 },
 121         [BAM_IRQ_SRCS_UNMASKED] = { 0x0FB0, 0x00, 0x00, 0x00 },
 122         [BAM_IRQ_STTS]          = { 0x0F94, 0x00, 0x00, 0x00 },
 123         [BAM_IRQ_CLR]           = { 0x0F98, 0x00, 0x00, 0x00 },
 124         [BAM_IRQ_EN]            = { 0x0F9C, 0x00, 0x00, 0x00 },
 125         [BAM_CNFG_BITS]         = { 0x0FFC, 0x00, 0x00, 0x00 },
 126         [BAM_IRQ_SRCS_EE]       = { 0x1800, 0x00, 0x00, 0x80 },
 127         [BAM_IRQ_SRCS_MSK_EE]   = { 0x1804, 0x00, 0x00, 0x80 },
 128         [BAM_P_CTRL]            = { 0x0000, 0x80, 0x00, 0x00 },
 129         [BAM_P_RST]             = { 0x0004, 0x80, 0x00, 0x00 },
 130         [BAM_P_HALT]            = { 0x0008, 0x80, 0x00, 0x00 },
 131         [BAM_P_IRQ_STTS]        = { 0x0010, 0x80, 0x00, 0x00 },
 132         [BAM_P_IRQ_CLR]         = { 0x0014, 0x80, 0x00, 0x00 },
 133         [BAM_P_IRQ_EN]          = { 0x0018, 0x80, 0x00, 0x00 },
 134         [BAM_P_EVNT_DEST_ADDR]  = { 0x102C, 0x00, 0x40, 0x00 },
 135         [BAM_P_EVNT_REG]        = { 0x1018, 0x00, 0x40, 0x00 },
 136         [BAM_P_SW_OFSTS]        = { 0x1000, 0x00, 0x40, 0x00 },
 137         [BAM_P_DATA_FIFO_ADDR]  = { 0x1024, 0x00, 0x40, 0x00 },
 138         [BAM_P_DESC_FIFO_ADDR]  = { 0x101C, 0x00, 0x40, 0x00 },
 139         [BAM_P_EVNT_GEN_TRSHLD] = { 0x1028, 0x00, 0x40, 0x00 },
 140         [BAM_P_FIFO_SIZES]      = { 0x1020, 0x00, 0x40, 0x00 },
 141 };
 142
 143 static const struct reg_offset_data bam_v1_4_reg_info[] = {
 144         [BAM_CTRL]              = { 0x0000, 0x00, 0x00, 0x00 },
 145         [BAM_REVISION]          = { 0x0004, 0x00, 0x00, 0x00 },
 146         [BAM_NUM_PIPES]         = { 0x003C, 0x00, 0x00, 0x00 },
 147         [BAM_DESC_CNT_TRSHLD]   = { 0x0008, 0x00, 0x00, 0x00 },
 148         [BAM_IRQ_SRCS]          = { 0x000C, 0x00, 0x00, 0x00 },
 149         [BAM_IRQ_SRCS_MSK]      = { 0x0010, 0x00, 0x00, 0x00 },
 150         [BAM_IRQ_SRCS_UNMASKED] = { 0x0030, 0x00, 0x00, 0x00 },
 151         [BAM_IRQ_STTS]          = { 0x0014, 0x00, 0x00, 0x00 },
 152         [BAM_IRQ_CLR]           = { 0x0018, 0x00, 0x00, 0x00 },
 153         [BAM_IRQ_EN]            = { 0x001C, 0x00, 0x00, 0x00 },
 154         [BAM_CNFG_BITS]         = { 0x007C, 0x00, 0x00, 0x00 },
 155         [BAM_IRQ_SRCS_EE]       = { 0x0800, 0x00, 0x00, 0x80 },
 156         [BAM_IRQ_SRCS_MSK_EE]   = { 0x0804, 0x00, 0x00, 0x80 },
 157         [BAM_P_CTRL]            = { 0x1000, 0x1000, 0x00, 0x00 },
 158         [BAM_P_RST]             = { 0x1004, 0x1000, 0x00, 0x00 },
 159         [BAM_P_HALT]            = { 0x1008, 0x1000, 0x00, 0x00 },
 160         [BAM_P_IRQ_STTS]        = { 0x1010, 0x1000, 0x00, 0x00 },
 161         [BAM_P_IRQ_CLR]         = { 0x1014, 0x1000, 0x00, 0x00 },
 162         [BAM_P_IRQ_EN]          = { 0x1018, 0x1000, 0x00, 0x00 },
 163         [BAM_P_EVNT_DEST_ADDR]  = { 0x182C, 0x00, 0x1000, 0x00 },
 164         [BAM_P_EVNT_REG]        = { 0x1818, 0x00, 0x1000, 0x00 },
 165         [BAM_P_SW_OFSTS]        = { 0x1800, 0x00, 0x1000, 0x00 },
 166         [BAM_P_DATA_FIFO_ADDR]  = { 0x1824, 0x00, 0x1000, 0x00 },
 167         [BAM_P_DESC_FIFO_ADDR]  = { 0x181C, 0x00, 0x1000, 0x00 },
 168         [BAM_P_EVNT_GEN_TRSHLD] = { 0x1828, 0x00, 0x1000, 0x00 },
 169         [BAM_P_FIFO_SIZES]      = { 0x1820, 0x00, 0x1000, 0x00 },
 170 };
 171
 172 static const struct reg_offset_data bam_v1_7_reg_info[] = {
 173         [BAM_CTRL]              = { 0x00000, 0x00, 0x00, 0x00 },
 174         [BAM_REVISION]          = { 0x01000, 0x00, 0x00, 0x00 },
 175         [BAM_NUM_PIPES]         = { 0x01008, 0x00, 0x00, 0x00 },
 176         [BAM_DESC_CNT_TRSHLD]   = { 0x00008, 0x00, 0x00, 0x00 },
 177         [BAM_IRQ_SRCS]          = { 0x03010, 0x00, 0x00, 0x00 },
 178         [BAM_IRQ_SRCS_MSK]      = { 0x03014, 0x00, 0x00, 0x00 },
 179         [BAM_IRQ_SRCS_UNMASKED] = { 0x03018, 0x00, 0x00, 0x00 },
 180         [BAM_IRQ_STTS]          = { 0x00014, 0x00, 0x00, 0x00 },
 181         [BAM_IRQ_CLR]           = { 0x00018, 0x00, 0x00, 0x00 },
 182         [BAM_IRQ_EN]            = { 0x0001C, 0x00, 0x00, 0x00 },
 183         [BAM_CNFG_BITS]         = { 0x0007C, 0x00, 0x00, 0x00 },
 184         [BAM_IRQ_SRCS_EE]       = { 0x03000, 0x00, 0x00, 0x1000 },
 185         [BAM_IRQ_SRCS_MSK_EE]   = { 0x03004, 0x00, 0x00, 0x1000 },
 186         [BAM_P_CTRL]            = { 0x13000, 0x1000, 0x00, 0x00 },
 187         [BAM_P_RST]             = { 0x13004, 0x1000, 0x00, 0x00 },
 188         [BAM_P_HALT]            = { 0x13008, 0x1000, 0x00, 0x00 },
 189         [BAM_P_IRQ_STTS]        = { 0x13010, 0x1000, 0x00, 0x00 },
 190         [BAM_P_IRQ_CLR]         = { 0x13014, 0x1000, 0x00, 0x00 },
 191         [BAM_P_IRQ_EN]          = { 0x13018, 0x1000, 0x00, 0x00 },
 192         [BAM_P_EVNT_DEST_ADDR]  = { 0x1382C, 0x00, 0x1000, 0x00 },
 193         [BAM_P_EVNT_REG]        = { 0x13818, 0x00, 0x1000, 0x00 },
 194         [BAM_P_SW_OFSTS]        = { 0x13800, 0x00, 0x1000, 0x00 },
 195         [BAM_P_DATA_FIFO_ADDR]  = { 0x13824, 0x00, 0x1000, 0x00 },
 196         [BAM_P_DESC_FIFO_ADDR]  = { 0x1381C, 0x00, 0x1000, 0x00 },
 197         [BAM_P_EVNT_GEN_TRSHLD] = { 0x13828, 0x00, 0x1000, 0x00 },
 198         [BAM_P_FIFO_SIZES]      = { 0x13820, 0x00, 0x1000, 0x00 },
 199 };
 200
 201 /* BAM CTRL */
 202 #define BAM_SW_RST                      BIT(0)
 203 #define BAM_EN                          BIT(1)
 204 #define BAM_EN_ACCUM                    BIT(4)
 205 #define BAM_TESTBUS_SEL_SHIFT           5
 206 #define BAM_TESTBUS_SEL_MASK            0x3F
 207 #define BAM_DESC_CACHE_SEL_SHIFT        13
 208 #define BAM_DESC_CACHE_SEL_MASK         0x3
 209 #define BAM_CACHED_DESC_STORE           BIT(15)
 210 #define IBC_DISABLE                     BIT(16)
 211
 212 /* BAM REVISION */
 213 #define REVISION_SHIFT          0
 214 #define REVISION_MASK           0xFF
 215 #define NUM_EES_SHIFT           8
 216 #define NUM_EES_MASK            0xF
 217 #define CE_BUFFER_SIZE          BIT(13)
 218 #define AXI_ACTIVE              BIT(14)
 219 #define USE_VMIDMT              BIT(15)
 220 #define SECURED                 BIT(16)
 221 #define BAM_HAS_NO_BYPASS       BIT(17)
 222 #define HIGH_FREQUENCY_BAM      BIT(18)
 223 #define INACTIV_TMRS_EXST       BIT(19)
 224 #define NUM_INACTIV_TMRS        BIT(20)
 225 #define DESC_CACHE_DEPTH_SHIFT  21
 226 #define DESC_CACHE_DEPTH_1      (0 << DESC_CACHE_DEPTH_SHIFT)
 227 #define DESC_CACHE_DEPTH_2      (1 << DESC_CACHE_DEPTH_SHIFT)
 228 #define DESC_CACHE_DEPTH_3      (2 << DESC_CACHE_DEPTH_SHIFT)
 229 #define DESC_CACHE_DEPTH_4      (3 << DESC_CACHE_DEPTH_SHIFT)
 230 #define CMD_DESC_EN             BIT(23)
 231 #define INACTIV_TMR_BASE_SHIFT  24
 232 #define INACTIV_TMR_BASE_MASK   0xFF
 233
 234 /* BAM NUM PIPES */
 235 #define BAM_NUM_PIPES_SHIFT             0
 236 #define BAM_NUM_PIPES_MASK              0xFF
 237 #define PERIPH_NON_PIPE_GRP_SHIFT       16
 238 #define PERIPH_NON_PIP_GRP_MASK         0xFF
 239 #define BAM_NON_PIPE_GRP_SHIFT          24
 240 #define BAM_NON_PIPE_GRP_MASK           0xFF
 241
 242 /* BAM CNFG BITS */
 243 #define BAM_PIPE_CNFG           BIT(2)
 244 #define BAM_FULL_PIPE           BIT(11)
 245 #define BAM_NO_EXT_P_RST        BIT(12)
 246 #define BAM_IBC_DISABLE         BIT(13)
 247 #define BAM_SB_CLK_REQ          BIT(14)
 248 #define BAM_PSM_CSW_REQ         BIT(15)
 249 #define BAM_PSM_P_RES           BIT(16)
 250 #define BAM_AU_P_RES            BIT(17)
 251 #define BAM_SI_P_RES            BIT(18)
 252 #define BAM_WB_P_RES            BIT(19)
 253 #define BAM_WB_BLK_CSW          BIT(20)
 254 #define BAM_WB_CSW_ACK_IDL      BIT(21)
 255 #define BAM_WB_RETR_SVPNT       BIT(22)
 256 #define BAM_WB_DSC_AVL_P_RST    BIT(23)
 257 #define BAM_REG_P_EN            BIT(24)
 258 #define BAM_PSM_P_HD_DATA       BIT(25)
 259 #define BAM_AU_ACCUMED          BIT(26)
 260 #define BAM_CMD_ENABLE          BIT(27)
 261
 262 #define BAM_CNFG_BITS_DEFAULT   (BAM_PIPE_CNFG |        \
 263                                  BAM_NO_EXT_P_RST |     \
 264                                  BAM_IBC_DISABLE |      \
 265                                  BAM_SB_CLK_REQ |       \
 266                                  BAM_PSM_CSW_REQ |      \
 267                                  BAM_PSM_P_RES |        \
 268                                  BAM_AU_P_RES |         \
 269                                  BAM_SI_P_RES |         \
 270                                  BAM_WB_P_RES |         \
 271                                  BAM_WB_BLK_CSW |       \
 272                                  BAM_WB_CSW_ACK_IDL |   \
 273                                  BAM_WB_RETR_SVPNT |    \
 274                                  BAM_WB_DSC_AVL_P_RST | \
 275                                  BAM_REG_P_EN |         \
 276                                  BAM_PSM_P_HD_DATA |    \
 277                                  BAM_AU_ACCUMED |       \
 278                                  BAM_CMD_ENABLE)
 279
 280 /* PIPE CTRL */
 281 #define P_EN                    BIT(1)
 282 #define P_DIRECTION             BIT(3)
 283 #define P_SYS_STRM              BIT(4)
 284 #define P_SYS_MODE              BIT(5)
 285 #define P_AUTO_EOB              BIT(6)
 286 #define P_AUTO_EOB_SEL_SHIFT    7
 287 #define P_AUTO_EOB_SEL_512      (0 << P_AUTO_EOB_SEL_SHIFT)
 288 #define P_AUTO_EOB_SEL_256      (1 << P_AUTO_EOB_SEL_SHIFT)
 289 #define P_AUTO_EOB_SEL_128      (2 << P_AUTO_EOB_SEL_SHIFT)
 290 #define P_AUTO_EOB_SEL_64       (3 << P_AUTO_EOB_SEL_SHIFT)
 291 #define P_PREFETCH_LIMIT_SHIFT  9
 292 #define P_PREFETCH_LIMIT_32     (0 << P_PREFETCH_LIMIT_SHIFT)
 293 #define P_PREFETCH_LIMIT_16     (1 << P_PREFETCH_LIMIT_SHIFT)
 294 #define P_PREFETCH_LIMIT_4      (2 << P_PREFETCH_LIMIT_SHIFT)
 295 #define P_WRITE_NWD             BIT(11)
 296 #define P_LOCK_GROUP_SHIFT      16
 297 #define P_LOCK_GROUP_MASK       0x1F
 298
 299 /* BAM_DESC_CNT_TRSHLD */
 300 #define CNT_TRSHLD              0xffff
 301 #define DEFAULT_CNT_THRSHLD     0x4
 302
 303 /* BAM_IRQ_SRCS */
 304 #define BAM_IRQ                 BIT(31)
 305 #define P_IRQ                   0x7fffffff
 306
 307 /* BAM_IRQ_SRCS_MSK */
 308 #define BAM_IRQ_MSK             BAM_IRQ
 309 #define P_IRQ_MSK               P_IRQ
 310
 311 /* BAM_IRQ_STTS */
 312 #define BAM_TIMER_IRQ           BIT(4)
 313 #define BAM_EMPTY_IRQ           BIT(3)
 314 #define BAM_ERROR_IRQ           BIT(2)
 315 #define BAM_HRESP_ERR_IRQ       BIT(1)
 316
 317 /* BAM_IRQ_CLR */
 318 #define BAM_TIMER_CLR           BIT(4)
 319 #define BAM_EMPTY_CLR           BIT(3)
 320 #define BAM_ERROR_CLR           BIT(2)
 321 #define BAM_HRESP_ERR_CLR       BIT(1)
 322
 323 /* BAM_IRQ_EN */
 324 #define BAM_TIMER_EN            BIT(4)
 325 #define BAM_EMPTY_EN            BIT(3)
 326 #define BAM_ERROR_EN            BIT(2)
 327 #define BAM_HRESP_ERR_EN        BIT(1)
 328
 329 /* BAM_P_IRQ_EN */
 330 #define P_PRCSD_DESC_EN         BIT(0)
 331 #define P_TIMER_EN              BIT(1)
 332 #define P_WAKE_EN               BIT(2)
 333 #define P_OUT_OF_DESC_EN        BIT(3)
 334 #define P_ERR_EN                BIT(4)
 335 #define P_TRNSFR_END_EN         BIT(5)
 336 #define P_DEFAULT_IRQS_EN       (P_PRCSD_DESC_EN | P_ERR_EN | P_TRNSFR_END_EN)
 337
 338 /* BAM_P_SW_OFSTS */
 339 #define P_SW_OFSTS_MASK         0xffff
 340
 341 #define BAM_DESC_FIFO_SIZE      SZ_32K
 342 #define MAX_DESCRIPTORS (BAM_DESC_FIFO_SIZE / sizeof(struct bam_desc_hw) - 1)
 343 #define BAM_FIFO_SIZE   (SZ_32K - 8)
 344 #define IS_BUSY(chan)   (CIRC_SPACE(bchan->tail, bchan->head,\
 345                          MAX_DESCRIPTORS + 1) == 0)
 346
 347 struct bam_chan {
 348         struct virt_dma_chan vc;
 349
 350         struct bam_device *bdev;
 351
 352         /* configuration from device tree */
 353         u32 id;
 354
 355         /* runtime configuration */
 356         struct dma_slave_config slave;
 357
 358         /* fifo storage */
 359         struct bam_desc_hw *fifo_virt;
 360         dma_addr_t fifo_phys;
 361
 362         /* fifo markers */
 363         unsigned short head;            /* start of active descriptor entries */
 364         unsigned short tail;            /* end of active descriptor entries */
 365
 366         unsigned int initialized;       /* is the channel hw initialized? */
 367         unsigned int paused;            /* is the channel paused? */
 368         unsigned int reconfigure;       /* new slave config? */
 369         /* list of descriptors currently processed */
 370         struct list_head desc_list;
 371
 372         struct list_head node;
 373 };
 374
 375 static inline struct bam_chan *to_bam_chan(struct dma_chan *common)
 376 {
 377         return container_of(common, struct bam_chan, vc.chan);
 378 }
 379
 380 struct bam_device {
 381         void __iomem *regs;
 382         struct device *dev;
 383         struct dma_device common;
 384         struct bam_chan *channels;
 385         u32 num_channels;
 386         u32 num_ees;
 387
 388         /* execution environment ID, from DT */
 389         u32 ee;
 390         bool controlled_remotely;
 391
 392         const struct reg_offset_data *layout;
 393
 394         struct clk *bamclk;
 395         int irq;
 396
 397         /* dma start transaction tasklet */
 398         struct tasklet_struct task;
 399 };
 400
 401 /**
 402  * bam_addr - returns BAM register address
 403  * @bdev: bam device
 404  * @pipe: pipe instance (ignored when register doesn't have multiple instances)
 405  * @reg:  register enum
 406  */
 407 static inline void __iomem *bam_addr(struct bam_device *bdev, u32 pipe,
 408                 enum bam_reg reg)
 409 {
 410         const struct reg_offset_data r = bdev->layout[reg];
 411
 412         return bdev->regs + r.base_offset +
 413                 r.pipe_mult * pipe +
 414                 r.evnt_mult * pipe +
 415                 r.ee_mult * bdev->ee;
 416 }
 417
 418 /**
 419  * bam_reset_channel - Reset individual BAM DMA channel
 420  * @bchan: bam channel
 421  *
 422  * This function resets a specific BAM channel
 423  */
 424 static void bam_reset_channel(struct bam_chan *bchan)
 425 {
 426         struct bam_device *bdev = bchan->bdev;
 427
 428         lockdep_assert_held(&bchan->vc.lock);
 429
 430         /* reset channel */
 431         writel_relaxed(1, bam_addr(bdev, bchan->id, BAM_P_RST));
 432         writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_RST));
 433
 434         /* don't allow cpu to reorder BAM register accesses done after this */
 435         wmb();
 436
 437         /* make sure hw is initialized when channel is used the first time  */
 438         bchan->initialized = 0;
 439 }
 440
 441 /**
 442  * bam_chan_init_hw - Initialize channel hardware
 443  * @bchan: bam channel
 444  * @dir: DMA transfer direction
 445  *
 446  * This function resets and initializes the BAM channel
 447  */
 448 static void bam_chan_init_hw(struct bam_chan *bchan,
 449         enum dma_transfer_direction dir)
 450 {
 451         struct bam_device *bdev = bchan->bdev;
 452         u32 val;
 453
 454         /* Reset the channel to clear internal state of the FIFO */
 455         bam_reset_channel(bchan);
 456
 457         /*
 458          * write out 8 byte aligned address.  We have enough space for this
 459          * because we allocated 1 more descriptor (8 bytes) than we can use
 460          */
 461         writel_relaxed(ALIGN(bchan->fifo_phys, sizeof(struct bam_desc_hw)),
 462                         bam_addr(bdev, bchan->id, BAM_P_DESC_FIFO_ADDR));
 463         writel_relaxed(BAM_FIFO_SIZE,
 464                         bam_addr(bdev, bchan->id, BAM_P_FIFO_SIZES));
 465
 466         /* enable the per pipe interrupts, enable EOT, ERR, and INT irqs */
 467         writel_relaxed(P_DEFAULT_IRQS_EN,
 468                         bam_addr(bdev, bchan->id, BAM_P_IRQ_EN));
 469
 470         /* unmask the specific pipe and EE combo */
 471         val = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
 472         val |= BIT(bchan->id);
 473         writel_relaxed(val, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
 474
 475         /* don't allow cpu to reorder the channel enable done below */
 476         wmb();
 477
 478         /* set fixed direction and mode, then enable channel */
 479         val = P_EN | P_SYS_MODE;
 480         if (dir == DMA_DEV_TO_MEM)
 481                 val |= P_DIRECTION;
 482
 483         writel_relaxed(val, bam_addr(bdev, bchan->id, BAM_P_CTRL));
 484
 485         bchan->initialized = 1;
 486
 487         /* init FIFO pointers */
 488         bchan->head = 0;
 489         bchan->tail = 0;
 490 }
 491
 492 /**
 493  * bam_alloc_chan - Allocate channel resources for DMA channel.
 494  * @chan: specified channel
 495  *
 496  * This function allocates the FIFO descriptor memory
 497  */
 498 static int bam_alloc_chan(struct dma_chan *chan)
 499 {
 500         struct bam_chan *bchan = to_bam_chan(chan);
 501         struct bam_device *bdev = bchan->bdev;
 502
 503         if (bchan->fifo_virt)
 504                 return 0;
 505
 506         /* allocate FIFO descriptor space, but only if necessary */
 507         bchan->fifo_virt = dma_alloc_wc(bdev->dev, BAM_DESC_FIFO_SIZE,
 508                                         &bchan->fifo_phys, GFP_KERNEL);
 509
 510         if (!bchan->fifo_virt) {
 511                 dev_err(bdev->dev, "Failed to allocate desc fifo\n");
 512                 return -ENOMEM;
 513         }
 514
 515         return 0;
 516 }
 517
 518 static int bam_pm_runtime_get_sync(struct device *dev)
 519 {
 520         if (pm_runtime_enabled(dev))
 521                 return pm_runtime_get_sync(dev);
 522
 523         return 0;
 524 }
 525
 526 /**
 527  * bam_free_chan - Frees dma resources associated with specific channel
 528  * @chan: specified channel
 529  *
 530  * Free the allocated fifo descriptor memory and channel resources
 531  *
 532  */
 533 static void bam_free_chan(struct dma_chan *chan)
 534 {
 535         struct bam_chan *bchan = to_bam_chan(chan);
 536         struct bam_device *bdev = bchan->bdev;
 537         u32 val;
 538         unsigned long flags;
 539         int ret;
 540
 541         ret = bam_pm_runtime_get_sync(bdev->dev);
 542         if (ret < 0)
 543                 return;
 544
 545         vchan_free_chan_resources(to_virt_chan(chan));
 546
 547         if (!list_empty(&bchan->desc_list)) {
 548                 dev_err(bchan->bdev->dev, "Cannot free busy channel\n");
 549                 goto err;
 550         }
 551
 552         spin_lock_irqsave(&bchan->vc.lock, flags);
 553         bam_reset_channel(bchan);
 554         spin_unlock_irqrestore(&bchan->vc.lock, flags);
 555
 556         dma_free_wc(bdev->dev, BAM_DESC_FIFO_SIZE, bchan->fifo_virt,
 557                     bchan->fifo_phys);
 558         bchan->fifo_virt = NULL;
 559
 560         /* mask irq for pipe/channel */
 561         val = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
 562         val &= ~BIT(bchan->id);
 563         writel_relaxed(val, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
 564
 565         /* disable irq */
 566         writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_IRQ_EN));
 567
 568 err:
 569         pm_runtime_mark_last_busy(bdev->dev);
 570         pm_runtime_put_autosuspend(bdev->dev);
 571 }
 572
 573 /**
 574  * bam_slave_config - set slave configuration for channel
 575  * @chan: dma channel
 576  * @cfg: slave configuration
 577  *
 578  * Sets slave configuration for channel
 579  *
 580  */
 581 static int bam_slave_config(struct dma_chan *chan,
 582                             struct dma_slave_config *cfg)
 583 {
 584         struct bam_chan *bchan = to_bam_chan(chan);
 585         unsigned long flag;
 586
 587         spin_lock_irqsave(&bchan->vc.lock, flag);
 588         memcpy(&bchan->slave, cfg, sizeof(*cfg));
 589         bchan->reconfigure = 1;
 590         spin_unlock_irqrestore(&bchan->vc.lock, flag);
 591
 592         return 0;
 593 }
 594
 595 /**
 596  * bam_prep_slave_sg - Prep slave sg transaction
 597  *
 598  * @chan: dma channel
 599  * @sgl: scatter gather list
 600  * @sg_len: length of sg
 601  * @direction: DMA transfer direction
 602  * @flags: DMA flags
 603  * @context: transfer context (unused)
 604  */
 605 static struct dma_async_tx_descriptor *bam_prep_slave_sg(struct dma_chan *chan,
 606         struct scatterlist *sgl, unsigned int sg_len,
 607         enum dma_transfer_direction direction, unsigned long flags,
 608         void *context)
 609 {
 610         struct bam_chan *bchan = to_bam_chan(chan);
 611         struct bam_device *bdev = bchan->bdev;
 612         struct bam_async_desc *async_desc;
 613         struct scatterlist *sg;
 614         u32 i;
 615         struct bam_desc_hw *desc;
 616         unsigned int num_alloc = 0;
 617
 618
 619         if (!is_slave_direction(direction)) {
 620                 dev_err(bdev->dev, "invalid dma direction\n");
 621                 return NULL;
 622         }
 623
 624         /* calculate number of required entries */
 625         for_each_sg(sgl, sg, sg_len, i)
 626                 num_alloc += DIV_ROUND_UP(sg_dma_len(sg), BAM_FIFO_SIZE);
 627
 628         /* allocate enough room to accomodate the number of entries */
 629         async_desc = kzalloc(struct_size(async_desc, desc, num_alloc),
 630                              GFP_NOWAIT);
 631
 632         if (!async_desc)
 633                 goto err_out;
 634
 635         if (flags & DMA_PREP_FENCE)
 636                 async_desc->flags |= DESC_FLAG_NWD;
 637
 638         if (flags & DMA_PREP_INTERRUPT)
 639                 async_desc->flags |= DESC_FLAG_EOT;
 640
 641         async_desc->num_desc = num_alloc;
 642         async_desc->curr_desc = async_desc->desc;
 643         async_desc->dir = direction;
 644
 645         /* fill in temporary descriptors */
 646         desc = async_desc->desc;
 647         for_each_sg(sgl, sg, sg_len, i) {
 648                 unsigned int remainder = sg_dma_len(sg);
 649                 unsigned int curr_offset = 0;
 650
 651                 do {
 652                         if (flags & DMA_PREP_CMD)
 653                                 desc->flags |= cpu_to_le16(DESC_FLAG_CMD);
 654
 655                         desc->addr = cpu_to_le32(sg_dma_address(sg) +
 656                                                  curr_offset);
 657
 658                         if (remainder > BAM_FIFO_SIZE) {
 659                                 desc->size = cpu_to_le16(BAM_FIFO_SIZE);
 660                                 remainder -= BAM_FIFO_SIZE;
 661                                 curr_offset += BAM_FIFO_SIZE;
 662                         } else {
 663                                 desc->size = cpu_to_le16(remainder);
 664                                 remainder = 0;
 665                         }
 666
 667                         async_desc->length += le16_to_cpu(desc->size);
 668                         desc++;
 669                 } while (remainder > 0);
 670         }
 671
 672         return vchan_tx_prep(&bchan->vc, &async_desc->vd, flags);
 673
 674 err_out:
 675         kfree(async_desc);
 676         return NULL;
 677 }
 678
 679 /**
 680  * bam_dma_terminate_all - terminate all transactions on a channel
 681  * @chan: bam dma channel
 682  *
 683  * Dequeues and frees all transactions
 684  * No callbacks are done
 685  *
 686  */
 687 static int bam_dma_terminate_all(struct dma_chan *chan)
 688 {
 689         struct bam_chan *bchan = to_bam_chan(chan);
 690         struct bam_async_desc *async_desc, *tmp;
 691         unsigned long flag;
 692         LIST_HEAD(head);
 693
 694         /* remove all transactions, including active transaction */
 695         spin_lock_irqsave(&bchan->vc.lock, flag);
 696         /*
 697          * If we have transactions queued, then some might be committed to the
 698          * hardware in the desc fifo.  The only way to reset the desc fifo is
 699          * to do a hardware reset (either by pipe or the entire block).
 700          * bam_chan_init_hw() will trigger a pipe reset, and also reinit the
 701          * pipe.  If the pipe is left disabled (default state after pipe reset)
 702          * and is accessed by a connected hardware engine, a fatal error in
 703          * the BAM will occur.  There is a small window where this could happen
 704          * with bam_chan_init_hw(), but it is assumed that the caller has
 705          * stopped activity on any attached hardware engine.  Make sure to do
 706          * this first so that the BAM hardware doesn't cause memory corruption
 707          * by accessing freed resources.
 708          */
 709         if (!list_empty(&bchan->desc_list)) {
 710                 async_desc = list_first_entry(&bchan->desc_list,
 711                                               struct bam_async_desc, desc_node);
 712                 bam_chan_init_hw(bchan, async_desc->dir);
 713         }
 714
 715         list_for_each_entry_safe(async_desc, tmp,
 716                                  &bchan->desc_list, desc_node) {
 717                 list_add(&async_desc->vd.node, &bchan->vc.desc_issued);
 718                 list_del(&async_desc->desc_node);
 719         }
 720
 721         vchan_get_all_descriptors(&bchan->vc, &head);
 722         spin_unlock_irqrestore(&bchan->vc.lock, flag);
 723
 724         vchan_dma_desc_free_list(&bchan->vc, &head);
 725
 726         return 0;
 727 }
 728
 729 /**
 730  * bam_pause - Pause DMA channel
 731  * @chan: dma channel
 732  *
 733  */
 734 static int bam_pause(struct dma_chan *chan)
 735 {
 736         struct bam_chan *bchan = to_bam_chan(chan);
 737         struct bam_device *bdev = bchan->bdev;
 738         unsigned long flag;
 739         int ret;
 740
 741         ret = bam_pm_runtime_get_sync(bdev->dev);
 742         if (ret < 0)
 743                 return ret;
 744
 745         spin_lock_irqsave(&bchan->vc.lock, flag);
 746         writel_relaxed(1, bam_addr(bdev, bchan->id, BAM_P_HALT));
 747         bchan->paused = 1;
 748         spin_unlock_irqrestore(&bchan->vc.lock, flag);
 749         pm_runtime_mark_last_busy(bdev->dev);
 750         pm_runtime_put_autosuspend(bdev->dev);
 751
 752         return 0;
 753 }
 754
 755 /**
 756  * bam_resume - Resume DMA channel operations
 757  * @chan: dma channel
 758  *
 759  */
 760 static int bam_resume(struct dma_chan *chan)
 761 {
 762         struct bam_chan *bchan = to_bam_chan(chan);
 763         struct bam_device *bdev = bchan->bdev;
 764         unsigned long flag;
 765         int ret;
 766
 767         ret = bam_pm_runtime_get_sync(bdev->dev);
 768         if (ret < 0)
 769                 return ret;
 770
 771         spin_lock_irqsave(&bchan->vc.lock, flag);
 772         writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_HALT));
 773         bchan->paused = 0;
 774         spin_unlock_irqrestore(&bchan->vc.lock, flag);
 775         pm_runtime_mark_last_busy(bdev->dev);
 776         pm_runtime_put_autosuspend(bdev->dev);
 777
 778         return 0;
 779 }
 780
 781 /**
 782  * process_channel_irqs - processes the channel interrupts
 783  * @bdev: bam controller
 784  *
 785  * This function processes the channel interrupts
 786  *
 787  */
 788 static u32 process_channel_irqs(struct bam_device *bdev)
 789 {
 790         u32 i, srcs, pipe_stts, offset, avail;
 791         unsigned long flags;
 792         struct bam_async_desc *async_desc, *tmp;
 793
 794         srcs = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_EE));
 795
 796         /* return early if no pipe/channel interrupts are present */
 797         if (!(srcs & P_IRQ))
 798                 return srcs;
 799
 800         for (i = 0; i < bdev->num_channels; i++) {
 801                 struct bam_chan *bchan = &bdev->channels[i];
 802
 803                 if (!(srcs & BIT(i)))
 804                         continue;
 805
 806                 /* clear pipe irq */
 807                 pipe_stts = readl_relaxed(bam_addr(bdev, i, BAM_P_IRQ_STTS));
 808
 809                 writel_relaxed(pipe_stts, bam_addr(bdev, i, BAM_P_IRQ_CLR));
 810
 811                 spin_lock_irqsave(&bchan->vc.lock, flags);
 812
 813                 offset = readl_relaxed(bam_addr(bdev, i, BAM_P_SW_OFSTS)) &
 814                                        P_SW_OFSTS_MASK;
 815                 offset /= sizeof(struct bam_desc_hw);
 816
 817                 /* Number of bytes available to read */
 818                 avail = CIRC_CNT(offset, bchan->head, MAX_DESCRIPTORS + 1);
 819
 820                 if (offset < bchan->head)
 821                         avail--;
 822
 823                 list_for_each_entry_safe(async_desc, tmp,
 824                                          &bchan->desc_list, desc_node) {
 825                         /* Not enough data to read */
 826                         if (avail < async_desc->xfer_len)
 827                                 break;
 828
 829                         /* manage FIFO */
 830                         bchan->head += async_desc->xfer_len;
 831                         bchan->head %= MAX_DESCRIPTORS;
 832
 833                         async_desc->num_desc -= async_desc->xfer_len;
 834                         async_desc->curr_desc += async_desc->xfer_len;
 835                         avail -= async_desc->xfer_len;
 836
 837                         /*
 838                          * if complete, process cookie. Otherwise
 839                          * push back to front of desc_issued so that
 840                          * it gets restarted by the tasklet
 841                          */
 842                         if (!async_desc->num_desc) {
 843                                 vchan_cookie_complete(&async_desc->vd);
 844                         } else {
 845                                 list_add(&async_desc->vd.node,
 846                                          &bchan->vc.desc_issued);
 847                         }
 848                         list_del(&async_desc->desc_node);
 849                 }
 850
 851                 spin_unlock_irqrestore(&bchan->vc.lock, flags);
 852         }
 853
 854         return srcs;
 855 }
 856
 857 /**
 858  * bam_dma_irq - irq handler for bam controller
 859  * @irq: IRQ of interrupt
 860  * @data: callback data
 861  *
 862  * IRQ handler for the bam controller
 863  */
 864 static irqreturn_t bam_dma_irq(int irq, void *data)
 865 {
 866         struct bam_device *bdev = data;
 867         u32 clr_mask = 0, srcs = 0;
 868         int ret;
 869
 870         srcs |= process_channel_irqs(bdev);
 871
 872         /* kick off tasklet to start next dma transfer */
 873         if (srcs & P_IRQ)
 874                 tasklet_schedule(&bdev->task);
 875
 876         ret = bam_pm_runtime_get_sync(bdev->dev);
 877         if (ret < 0)
 878                 return ret;
 879
 880         if (srcs & BAM_IRQ) {
 881                 clr_mask = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_STTS));
 882
 883                 /*
 884                  * don't allow reorder of the various accesses to the BAM
 885                  * registers
 886                  */
 887                 mb();
 888
 889                 writel_relaxed(clr_mask, bam_addr(bdev, 0, BAM_IRQ_CLR));
 890         }
 891
 892         pm_runtime_mark_last_busy(bdev->dev);
 893         pm_runtime_put_autosuspend(bdev->dev);
 894
 895         return IRQ_HANDLED;
 896 }
 897
 898 /**
 899  * bam_tx_status - returns status of transaction
 900  * @chan: dma channel
 901  * @cookie: transaction cookie
 902  * @txstate: DMA transaction state
 903  *
 904  * Return status of dma transaction
 905  */
 906 static enum dma_status bam_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
 907                 struct dma_tx_state *txstate)
 908 {
 909         struct bam_chan *bchan = to_bam_chan(chan);
 910         struct bam_async_desc *async_desc;
 911         struct virt_dma_desc *vd;
 912         int ret;
 913         size_t residue = 0;
 914         unsigned int i;
 915         unsigned long flags;
 916
 917         ret = dma_cookie_status(chan, cookie, txstate);
 918         if (ret == DMA_COMPLETE)
 919                 return ret;
 920
 921         if (!txstate)
 922                 return bchan->paused ? DMA_PAUSED : ret;
 923
 924         spin_lock_irqsave(&bchan->vc.lock, flags);
 925         vd = vchan_find_desc(&bchan->vc, cookie);
 926         if (vd) {
 927                 residue = container_of(vd, struct bam_async_desc, vd)->length;
 928         } else {
 929                 list_for_each_entry(async_desc, &bchan->desc_list, desc_node) {
 930                         if (async_desc->vd.tx.cookie != cookie)
 931                                 continue;
 932
 933                         for (i = 0; i < async_desc->num_desc; i++)
 934                                 residue += le16_to_cpu(
 935                                                 async_desc->curr_desc[i].size);
 936                 }
 937         }
 938
 939         spin_unlock_irqrestore(&bchan->vc.lock, flags);
 940
 941         dma_set_residue(txstate, residue);
 942
 943         if (ret == DMA_IN_PROGRESS && bchan->paused)
 944                 ret = DMA_PAUSED;
 945
 946         return ret;
 947 }
 948
 949 /**
 950  * bam_apply_new_config
 951  * @bchan: bam dma channel
 952  * @dir: DMA direction
 953  */
 954 static void bam_apply_new_config(struct bam_chan *bchan,
 955         enum dma_transfer_direction dir)
 956 {
 957         struct bam_device *bdev = bchan->bdev;
 958         u32 maxburst;
 959
 960         if (!bdev->controlled_remotely) {
 961                 if (dir == DMA_DEV_TO_MEM)
 962                         maxburst = bchan->slave.src_maxburst;
 963                 else
 964                         maxburst = bchan->slave.dst_maxburst;
 965
 966                 writel_relaxed(maxburst,
 967                                bam_addr(bdev, 0, BAM_DESC_CNT_TRSHLD));
 968         }
 969
 970         bchan->reconfigure = 0;
 971 }
 972
 973 /**
 974  * bam_start_dma - start next transaction
 975  * @bchan: bam dma channel
 976  */
 977 static void bam_start_dma(struct bam_chan *bchan)
 978 {
 979         struct virt_dma_desc *vd = vchan_next_desc(&bchan->vc);
 980         struct bam_device *bdev = bchan->bdev;
 981         struct bam_async_desc *async_desc = NULL;
 982         struct bam_desc_hw *desc;
 983         struct bam_desc_hw *fifo = PTR_ALIGN(bchan->fifo_virt,
 984                                         sizeof(struct bam_desc_hw));
 985         int ret;
 986         unsigned int avail;
 987         struct dmaengine_desc_callback cb;
 988
 989         lockdep_assert_held(&bchan->vc.lock);
 990
 991         if (!vd)
 992                 return;
 993
 994         ret = bam_pm_runtime_get_sync(bdev->dev);
 995         if (ret < 0)
 996                 return;
 997
 998         while (vd && !IS_BUSY(bchan)) {
 999                 list_del(&vd->node);
1000
1001                 async_desc = container_of(vd, struct bam_async_desc, vd);
1002
1003                 /* on first use, initialize the channel hardware */
1004                 if (!bchan->initialized)
1005                         bam_chan_init_hw(bchan, async_desc->dir);
1006
1007                 /* apply new slave config changes, if necessary */
1008                 if (bchan->reconfigure)
1009                         bam_apply_new_config(bchan, async_desc->dir);
1010
1011                 desc = async_desc->curr_desc;
1012                 avail = CIRC_SPACE(bchan->tail, bchan->head,
1013                                    MAX_DESCRIPTORS + 1);
1014
1015                 if (async_desc->num_desc > avail)
1016                         async_desc->xfer_len = avail;
1017                 else
1018                         async_desc->xfer_len = async_desc->num_desc;
1019
1020                 /* set any special flags on the last descriptor */
1021                 if (async_desc->num_desc == async_desc->xfer_len)
1022                         desc[async_desc->xfer_len - 1].flags |=
1023                                                 cpu_to_le16(async_desc->flags);
1024
1025                 vd = vchan_next_desc(&bchan->vc);
1026
1027                 dmaengine_desc_get_callback(&async_desc->vd.tx, &cb);
1028
1029                 /*
1030                  * An interrupt is generated at this desc, if
1031                  *  - FIFO is FULL.
1032                  *  - No more descriptors to add.
1033                  *  - If a callback completion was requested for this DESC,
1034                  *     In this case, BAM will deliver the completion callback
1035                  *     for this desc and continue processing the next desc.
1036                  */
1037                 if (((avail <= async_desc->xfer_len) || !vd ||
1038                      dmaengine_desc_callback_valid(&cb)) &&
1039                     !(async_desc->flags & DESC_FLAG_EOT))
1040                         desc[async_desc->xfer_len - 1].flags |=
1041                                 cpu_to_le16(DESC_FLAG_INT);
1042
1043                 if (bchan->tail + async_desc->xfer_len > MAX_DESCRIPTORS) {
1044                         u32 partial = MAX_DESCRIPTORS - bchan->tail;
1045
1046                         memcpy(&fifo[bchan->tail], desc,
1047                                partial * sizeof(struct bam_desc_hw));
1048                         memcpy(fifo, &desc[partial],
1049                                (async_desc->xfer_len - partial) *
1050                                 sizeof(struct bam_desc_hw));
1051                 } else {
1052                         memcpy(&fifo[bchan->tail], desc,
1053                                async_desc->xfer_len *
1054                                sizeof(struct bam_desc_hw));
1055                 }
1056
1057                 bchan->tail += async_desc->xfer_len;
1058                 bchan->tail %= MAX_DESCRIPTORS;
1059                 list_add_tail(&async_desc->desc_node, &bchan->desc_list);
1060         }
1061
1062         /* ensure descriptor writes and dma start not reordered */
1063         wmb();
1064         writel_relaxed(bchan->tail * sizeof(struct bam_desc_hw),
1065                         bam_addr(bdev, bchan->id, BAM_P_EVNT_REG));
1066
1067         pm_runtime_mark_last_busy(bdev->dev);
1068         pm_runtime_put_autosuspend(bdev->dev);
1069 }
1070
1071 /**
1072  * dma_tasklet - DMA IRQ tasklet
1073  * @t: tasklet argument (bam controller structure)
1074  *
1075  * Sets up next DMA operation and then processes all completed transactions
1076  */
1077 static void dma_tasklet(struct tasklet_struct *t)
1078 {
1079         struct bam_device *bdev = from_tasklet(bdev, t, task);
1080         struct bam_chan *bchan;
1081         unsigned long flags;
1082         unsigned int i;
1083
1084         /* go through the channels and kick off transactions */
1085         for (i = 0; i < bdev->num_channels; i++) {
1086                 bchan = &bdev->channels[i];
1087                 spin_lock_irqsave(&bchan->vc.lock, flags);
1088
1089                 if (!list_empty(&bchan->vc.desc_issued) && !IS_BUSY(bchan))
1090                         bam_start_dma(bchan);
1091                 spin_unlock_irqrestore(&bchan->vc.lock, flags);
1092         }
1093
1094 }
1095
1096 /**
1097  * bam_issue_pending - starts pending transactions
1098  * @chan: dma channel
1099  *
1100  * Calls tasklet directly which in turn starts any pending transactions
1101  */
1102 static void bam_issue_pending(struct dma_chan *chan)
1103 {
1104         struct bam_chan *bchan = to_bam_chan(chan);
1105         unsigned long flags;
1106
1107         spin_lock_irqsave(&bchan->vc.lock, flags);
1108
1109         /* if work pending and idle, start a transaction */
1110         if (vchan_issue_pending(&bchan->vc) && !IS_BUSY(bchan))
1111                 bam_start_dma(bchan);
1112
1113         spin_unlock_irqrestore(&bchan->vc.lock, flags);
1114 }
1115
1116 /**
1117  * bam_dma_free_desc - free descriptor memory
1118  * @vd: virtual descriptor
1119  *
1120  */
1121 static void bam_dma_free_desc(struct virt_dma_desc *vd)
1122 {
1123         struct bam_async_desc *async_desc = container_of(vd,
1124                         struct bam_async_desc, vd);
1125
1126         kfree(async_desc);
1127 }
1128
1129 static struct dma_chan *bam_dma_xlate(struct of_phandle_args *dma_spec,
1130                 struct of_dma *of)
1131 {
1132         struct bam_device *bdev = container_of(of->of_dma_data,
1133                                         struct bam_device, common);
1134         unsigned int request;
1135
1136         if (dma_spec->args_count != 1)
1137                 return NULL;
1138
1139         request = dma_spec->args[0];
1140         if (request >= bdev->num_channels)
1141                 return NULL;
1142
1143         return dma_get_slave_channel(&(bdev->channels[request].vc.chan));
1144 }
1145
1146 /**
1147  * bam_init
1148  * @bdev: bam device
1149  *
1150  * Initialization helper for global bam registers
1151  */
1152 static int bam_init(struct bam_device *bdev)
1153 {
1154         u32 val;
1155
1156         /* read revision and configuration information */
1157         if (!bdev->num_ees) {
1158                 val = readl_relaxed(bam_addr(bdev, 0, BAM_REVISION));
1159                 bdev->num_ees = (val >> NUM_EES_SHIFT) & NUM_EES_MASK;
1160         }
1161
1162         /* check that configured EE is within range */
1163         if (bdev->ee >= bdev->num_ees)
1164                 return -EINVAL;
1165
1166         if (!bdev->num_channels) {
1167                 val = readl_relaxed(bam_addr(bdev, 0, BAM_NUM_PIPES));
1168                 bdev->num_channels = val & BAM_NUM_PIPES_MASK;
1169         }
1170
1171         if (bdev->controlled_remotely)
1172                 return 0;
1173
1174         /* s/w reset bam */
1175         /* after reset all pipes are disabled and idle */
1176         val = readl_relaxed(bam_addr(bdev, 0, BAM_CTRL));
1177         val |= BAM_SW_RST;
1178         writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
1179         val &= ~BAM_SW_RST;
1180         writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
1181
1182         /* make sure previous stores are visible before enabling BAM */
1183         wmb();
1184
1185         /* enable bam */
1186         val |= BAM_EN;
1187         writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
1188
1189         /* set descriptor threshhold, start with 4 bytes */
1190         writel_relaxed(DEFAULT_CNT_THRSHLD,
1191                         bam_addr(bdev, 0, BAM_DESC_CNT_TRSHLD));
1192
1193         /* Enable default set of h/w workarounds, ie all except BAM_FULL_PIPE */
1194         writel_relaxed(BAM_CNFG_BITS_DEFAULT, bam_addr(bdev, 0, BAM_CNFG_BITS));
1195
1196         /* enable irqs for errors */
1197         writel_relaxed(BAM_ERROR_EN | BAM_HRESP_ERR_EN,
1198                         bam_addr(bdev, 0, BAM_IRQ_EN));
1199
1200         /* unmask global bam interrupt */
1201         writel_relaxed(BAM_IRQ_MSK, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
1202
1203         return 0;
1204 }
1205
1206 static void bam_channel_init(struct bam_device *bdev, struct bam_chan *bchan,
1207         u32 index)
1208 {
1209         bchan->id = index;
1210         bchan->bdev = bdev;
1211
1212         vchan_init(&bchan->vc, &bdev->common);
1213         bchan->vc.desc_free = bam_dma_free_desc;
1214         INIT_LIST_HEAD(&bchan->desc_list);
1215 }
1216
1217 static const struct of_device_id bam_of_match[] = {
1218         { .compatible = "qcom,bam-v1.3.0", .data = &bam_v1_3_reg_info },
1219         { .compatible = "qcom,bam-v1.4.0", .data = &bam_v1_4_reg_info },
1220         { .compatible = "qcom,bam-v1.7.0", .data = &bam_v1_7_reg_info },
1221         {}
1222 };
1223
1224 MODULE_DEVICE_TABLE(of, bam_of_match);
1225
1226 static int bam_dma_probe(struct platform_device *pdev)
1227 {
1228         struct bam_device *bdev;
1229         const struct of_device_id *match;
1230         struct resource *iores;
1231         int ret, i;
1232
1233         bdev = devm_kzalloc(&pdev->dev, sizeof(*bdev), GFP_KERNEL);
1234         if (!bdev)
1235                 return -ENOMEM;
1236
1237         bdev->dev = &pdev->dev;
1238
1239         match = of_match_node(bam_of_match, pdev->dev.of_node);
1240         if (!match) {
1241                 dev_err(&pdev->dev, "Unsupported BAM module\n");
1242                 return -ENODEV;
1243         }
1244
1245         bdev->layout = match->data;
1246
1247         iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1248         bdev->regs = devm_ioremap_resource(&pdev->dev, iores);
1249         if (IS_ERR(bdev->regs))
1250                 return PTR_ERR(bdev->regs);
1251
1252         bdev->irq = platform_get_irq(pdev, 0);
1253         if (bdev->irq < 0)
1254                 return bdev->irq;
1255
1256         ret = of_property_read_u32(pdev->dev.of_node, "qcom,ee", &bdev->ee);
1257         if (ret) {
1258                 dev_err(bdev->dev, "Execution environment unspecified\n");
1259                 return ret;
1260         }
1261
1262         bdev->controlled_remotely = of_property_read_bool(pdev->dev.of_node,
1263                                                 "qcom,controlled-remotely");
1264
1265         if (bdev->controlled_remotely) {
1266                 ret = of_property_read_u32(pdev->dev.of_node, "num-channels",
1267                                            &bdev->num_channels);
1268                 if (ret)
1269                         dev_err(bdev->dev, "num-channels unspecified in dt\n");
1270
1271                 ret = of_property_read_u32(pdev->dev.of_node, "qcom,num-ees",
1272                                            &bdev->num_ees);
1273                 if (ret)
1274                         dev_err(bdev->dev, "num-ees unspecified in dt\n");
1275         }
1276
1277         bdev->bamclk = devm_clk_get(bdev->dev, "bam_clk");
1278         if (IS_ERR(bdev->bamclk)) {
1279                 if (!bdev->controlled_remotely)
1280                         return PTR_ERR(bdev->bamclk);
1281
1282                 bdev->bamclk = NULL;
1283         }
1284
1285         ret = clk_prepare_enable(bdev->bamclk);
1286         if (ret) {
1287                 dev_err(bdev->dev, "failed to prepare/enable clock\n");
1288                 return ret;
1289         }
1290
1291         ret = bam_init(bdev);
1292         if (ret)
1293                 goto err_disable_clk;
1294
1295         tasklet_setup(&bdev->task, dma_tasklet);
1296
1297         bdev->channels = devm_kcalloc(bdev->dev, bdev->num_channels,
1298                                 sizeof(*bdev->channels), GFP_KERNEL);
1299
1300         if (!bdev->channels) {
1301                 ret = -ENOMEM;
1302                 goto err_tasklet_kill;
1303         }
1304
1305         /* allocate and initialize channels */
1306         INIT_LIST_HEAD(&bdev->common.channels);
1307
1308         for (i = 0; i < bdev->num_channels; i++)
1309                 bam_channel_init(bdev, &bdev->channels[i], i);
1310
1311         ret = devm_request_irq(bdev->dev, bdev->irq, bam_dma_irq,
1312                         IRQF_TRIGGER_HIGH, "bam_dma", bdev);
1313         if (ret)
1314                 goto err_bam_channel_exit;
1315
1316         /* set max dma segment size */
1317         bdev->common.dev = bdev->dev;
1318         ret = dma_set_max_seg_size(bdev->common.dev, BAM_FIFO_SIZE);
1319         if (ret) {
1320                 dev_err(bdev->dev, "cannot set maximum segment size\n");
1321                 goto err_bam_channel_exit;
1322         }
1323
1324         platform_set_drvdata(pdev, bdev);
1325
1326         /* set capabilities */
1327         dma_cap_zero(bdev->common.cap_mask);
1328         dma_cap_set(DMA_SLAVE, bdev->common.cap_mask);
1329
1330         /* initialize dmaengine apis */
1331         bdev->common.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
1332         bdev->common.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
1333         bdev->common.src_addr_widths = DMA_SLAVE_BUSWIDTH_4_BYTES;
1334         bdev->common.dst_addr_widths = DMA_SLAVE_BUSWIDTH_4_BYTES;
1335         bdev->common.device_alloc_chan_resources = bam_alloc_chan;
1336         bdev->common.device_free_chan_resources = bam_free_chan;
1337         bdev->common.device_prep_slave_sg = bam_prep_slave_sg;
1338         bdev->common.device_config = bam_slave_config;
1339         bdev->common.device_pause = bam_pause;
1340         bdev->common.device_resume = bam_resume;
1341         bdev->common.device_terminate_all = bam_dma_terminate_all;
1342         bdev->common.device_issue_pending = bam_issue_pending;
1343         bdev->common.device_tx_status = bam_tx_status;
1344         bdev->common.dev = bdev->dev;
1345
1346         ret = dma_async_device_register(&bdev->common);
1347         if (ret) {
1348                 dev_err(bdev->dev, "failed to register dma async device\n");
1349                 goto err_bam_channel_exit;
1350         }
1351
1352         ret = of_dma_controller_register(pdev->dev.of_node, bam_dma_xlate,
1353                                         &bdev->common);
1354         if (ret)
1355                 goto err_unregister_dma;
1356
1357         if (bdev->controlled_remotely) {
1358                 pm_runtime_disable(&pdev->dev);
1359                 return 0;
1360         }
1361
1362         pm_runtime_irq_safe(&pdev->dev);
1363         pm_runtime_set_autosuspend_delay(&pdev->dev, BAM_DMA_AUTOSUSPEND_DELAY);
1364         pm_runtime_use_autosuspend(&pdev->dev);
1365         pm_runtime_mark_last_busy(&pdev->dev);
1366         pm_runtime_set_active(&pdev->dev);
1367         pm_runtime_enable(&pdev->dev);
1368
1369         return 0;
1370
1371 err_unregister_dma:
1372         dma_async_device_unregister(&bdev->common);
1373 err_bam_channel_exit:
1374         for (i = 0; i < bdev->num_channels; i++)
1375                 tasklet_kill(&bdev->channels[i].vc.task);
1376 err_tasklet_kill:
1377         tasklet_kill(&bdev->task);
1378 err_disable_clk:
1379         clk_disable_unprepare(bdev->bamclk);
1380
1381         return ret;
1382 }
1383
1384 static int bam_dma_remove(struct platform_device *pdev)
1385 {
1386         struct bam_device *bdev = platform_get_drvdata(pdev);
1387         u32 i;
1388
1389         pm_runtime_force_suspend(&pdev->dev);
1390
1391         of_dma_controller_free(pdev->dev.of_node);
1392         dma_async_device_unregister(&bdev->common);
1393
1394         /* mask all interrupts for this execution environment */
1395         writel_relaxed(0, bam_addr(bdev, 0,  BAM_IRQ_SRCS_MSK_EE));
1396
1397         devm_free_irq(bdev->dev, bdev->irq, bdev);
1398
1399         for (i = 0; i < bdev->num_channels; i++) {
1400                 bam_dma_terminate_all(&bdev->channels[i].vc.chan);
1401                 tasklet_kill(&bdev->channels[i].vc.task);
1402
1403                 if (!bdev->channels[i].fifo_virt)
1404                         continue;
1405
1406                 dma_free_wc(bdev->dev, BAM_DESC_FIFO_SIZE,
1407                             bdev->channels[i].fifo_virt,
1408                             bdev->channels[i].fifo_phys);
1409         }
1410
1411         tasklet_kill(&bdev->task);
1412
1413         clk_disable_unprepare(bdev->bamclk);
1414
1415         return 0;
1416 }
1417
1418 static int __maybe_unused bam_dma_runtime_suspend(struct device *dev)
1419 {
1420         struct bam_device *bdev = dev_get_drvdata(dev);
1421
1422         clk_disable(bdev->bamclk);
1423
1424         return 0;
1425 }
1426
1427 static int __maybe_unused bam_dma_runtime_resume(struct device *dev)
1428 {
1429         struct bam_device *bdev = dev_get_drvdata(dev);
1430         int ret;
1431
1432         ret = clk_enable(bdev->bamclk);
1433         if (ret < 0) {
1434                 dev_err(dev, "clk_enable failed: %d\n", ret);
1435                 return ret;
1436         }
1437
1438         return 0;
1439 }
1440
1441 static int __maybe_unused bam_dma_suspend(struct device *dev)
1442 {
1443         struct bam_device *bdev = dev_get_drvdata(dev);
1444
1445         if (!bdev->controlled_remotely)
1446                 pm_runtime_force_suspend(dev);
1447
1448         clk_unprepare(bdev->bamclk);
1449
1450         return 0;
1451 }
1452
1453 static int __maybe_unused bam_dma_resume(struct device *dev)
1454 {
1455         struct bam_device *bdev = dev_get_drvdata(dev);
1456         int ret;
1457
1458         ret = clk_prepare(bdev->bamclk);
1459         if (ret)
1460                 return ret;
1461
1462         if (!bdev->controlled_remotely)
1463                 pm_runtime_force_resume(dev);
1464
1465         return 0;
1466 }
1467
1468 static const struct dev_pm_ops bam_dma_pm_ops = {
1469         SET_LATE_SYSTEM_SLEEP_PM_OPS(bam_dma_suspend, bam_dma_resume)
1470         SET_RUNTIME_PM_OPS(bam_dma_runtime_suspend, bam_dma_runtime_resume,
1471                                 NULL)
1472 };
1473
1474 static struct platform_driver bam_dma_driver = {
1475         .probe = bam_dma_probe,
1476         .remove = bam_dma_remove,
1477         .driver = {
1478                 .name = "bam-dma-engine",
1479                 .pm = &bam_dma_pm_ops,
1480                 .of_match_table = bam_of_match,
1481         },
1482 };
1483
1484 module_platform_driver(bam_dma_driver);
1485
1486 MODULE_AUTHOR("Andy Gross <agross@codeaurora.org>");
1487 MODULE_DESCRIPTION("QCOM BAM DMA engine driver");
1488 MODULE_LICENSE("GPL v2");